[PATCH] drm: parse color format support for digital displays

Jesse Barnes jbarnes at virtuousgeek.org
Fri Apr 15 12:44:32 PDT 2011

On Fri, 15 Apr 2011 15:36:22 -0400
Adam Jackson <ajax at redhat.com> wrote:

> On 4/15/11 3:19 PM, Jesse Barnes wrote:
> > Or is there a CEA block extension that allows for more granularity?
> CEA has bits for the two YCbCr formats too, which we should also parse 
> since there's plenty of 1.3+CEA blocks in the world thanks to HDMI.  For 
> CEA blocks version 2 and up (version number in byte 2 of the CEA block, 
> zero-based indexing), (1 << 5) of byte 3 is 4:4:4 and (1 << 4) is 4:2:2. 
>   Same byte as what we already check for EDID_BASIC_AUDIO, if that's any 
> clearer.  CEA spec contains the same language about always supporting 
> RGB though.

Ok, sounds good.  I can add that a separate function that runs after we
fill out display_info from the input & feature bits.

> I don't have a good answer for what to do if you have a 1.4+CEA block 
> and the two bitfields are inconsistent, besides violence against the 
> monitor vendor.

Hm I guess we'd take the CEA block instead as it's probably fresher at

Jesse Barnes, Intel Open Source Technology Center

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